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<p>Solar adaptive optics has become an indispensable tool at ground based solar telescopes. Driven by the quest for ever higher spatial resolution observations of the Sun solar adaptive optics are now operated routinely at major ground based solar telescopes. The current high-resolution solar telescopes, such as the Dunn Solar Telescope (DST), are in the one-meter class and utilize AO for &gt;95 % of the observing time to achieve the diffraction limit at visible and NIR wavelengths. Solar AO [1,2] has revitalized ground-based solar astronomy at existing telescopes. The development of high-order solar AO that is capable of delivering high Strehl in the visible will be absolutely essential for next generation solar telescopes, such as the 4m aperture Advanced Technology Solar Telescope (ATST), which undoubtedly will revolutionize solar astronomy [3]. Solar observations are performed over an extended field of view. The limited size of the isoplanatic patch, over which conventional adaptive optics (AO) provides diffraction limited resolution is a severe limitation. Solar science would benefit greatly from AO correction over large field of views. A single sunspot typically has a size of about 30 arcsec; large active regions often cover a field of 2-3 arcmin. Figure 1 shows an image of solar granulation and embedded magnetic g-band bright points observed near the limb of the sun. The field of view is approximately 120&quot;x 80&quot;. This diffraction limited image was recorded at the Dunn Solar Telescope with high order adaptive optics and post-processed using speckle interferometry. Post-processing is required to achieve the uniform, diffraction limited imaging over such an extended FOV. However, speckle interferometry as well as other post facto restoration methods typically rely on short exposure imaging, which in most cases can not be deployed when quantitative spectroscopy and polarimetry is performed, i.e., long exposures are required. Multi-conjugate adaptive optics (MCAO) is a technique that provides real-time diffraction limited imaging over an extended FOV [4]. The development of MCAO for existing solar telescopes and, in particular, for the next generation large aperture solar telescopes is thus a top priority. The Sun is an ideal object for the development of MCAO since solar structure provides &quot;multiple guide stars&quot; in any desired configuration. It is therefore not surprising that the first successful on-the-sky MCAO experiments were performed at the Dunn Solar Telescope and at a solar telescope on the Canary Islands. However, further development is needed before operational solar MCAO can be implemented at future large aperture solar telescopes such as the ATST on Haleakala [5]. MCAO development must progress beyond these initial proof-of-concept experiments and should include laboratory experiments and on-sky demonstrations under controlled or well characterized conditions as well as quantitative performance analysis and comparison to model predictions. At the DST we recently implemented a dedicated MCAO bench with the goal of developing well-characterized, operational MCAO. The MCAO system uses 2 deformable mirrors conjugated to the telescope entrance pupil and a layer in the upper atmosphere, respectively. DM2 can be placed at conjugates ranging from 2 km to 10 km altitude. For our initial experiments we have used a staged approach in which the 97 actuator, 76 subaperture correlating Shack-Hartmann solar adaptive optics system normally operated at the DST is followed by the second DM and the tomographic wavefront sensor, which uses three &quot;solar guide stars&quot;. We use modal reconstruction algorithms for both DMs. We have successfully and stably locked the MCAO system on artificial objects (slides), for which 1 The National Solar Observatory is operated by the Association of Universities for Research in Astronomy under a cooperative agreement with the National Science Foundation, for the benefit of the astronomical community turbulence screens are generated directly in front of the DMs, as well as solar structure. We varied the height of the upper conjugate between 2 km and 7 km. We recorded strictly simultaneous images after the pupil DM and after the upper layer DM. Comparing these images allows us to evaluate the performance of the MCAO stage and directly compare to the conventional AO. In addition we recorded wavefront sensor telemetry data for closed and open loop. We present preliminary results and discuss future plans.</p>